f(5x-2y=7" and "xy=2," find the value of "(5x+2y)^(2)

If x:y=2:3, find the value of (3x+2y):(2x+5y)

If 3x+5y=11 and xy=2, find the value of 9x^(2)+25y^(2)

If x=2 and y=5 find the values of : 7xy

(i) x+2y=-7 and 3x-2y=-1, then find the value of x. (ii) If x+y=8 and 4y-x=2, then find the value of y. (iii) If 3x+5y=9 and 5x+3y=7, then find the value of x+y. (iv) If 3x-y=11 and x-3y=17, then find the value of x-y.

If x=(sqrt7+sqrt3)/(sqrt7-sqrt3) and xy=1 find the value of (x^2+y^2+5xy)/(x^2+y^2-5xy)

If x= (sqrt5+1)/(sqrt5-1) and x = 1/y then find the value of (3x^(2) -7xy + 3y^(2))

If x=5 and y=-2 , then find the value of (i) (8x-2y+5)/(2x+4ty+12) " "(ii) (5x-6y-7)/(3x+6y+12)

If x:y= 3: 4, then the value of (5x - 2y)/(7x + 2y) =

If x : y = 4 : 7 , find the value of (3x + 2y) : (5x + y) .

If f(2x + 3y, 2x-3y)=4xy , then find the value of f(x,y)